Auxiliary Air Regulator
- Engine must be cold to perform this test. Start engine and run at idle speed. Pinch air regulator-to-intake manifold hose. RPM must drop.
- Run engine at idle speed for about 5 minutes more. Repeat test. RPM should not drop.
- If RPM changes when engine is warm, unplug electrical connector from air regulator. Check for voltage with engine running. If good, replace auxiliary air regulator.